What is the axis of symmetry for f(x) = -3x² + 18x - 7 ?

Solution:

Given f(x) = -3x² + 18x - 7,

Let y = -3x² + 18x - 7

⇒y = -3[x² - 6x + (7/3)]

⇒y = -3[x² - 6x + 9 - 9 + (7/3)]

⇒y = -3(x - 3)² - 20

⇒(x - 3)² = (-1/3)(y + 20) it is of the form (x - h)² = 4a (y - k) is a parabola whose vertex is at (3, -20)

Therefore, the axis of symmetry is x = 3

What is the axis of symmetry for f(x) = -3x² + 18x - 7 ?

Summary:

The axis of symmetry for f(x) = -3x² + 18x - 7 is x = 3.